Abstract: A method for detecting a contact point of a brake mechanism. The brake mechanism includes an actuator controlled by a motor. The method includes the steps of establishing a parameter of the motor and a derivative of the parameter and, if the parameter has passed a previous value under no load conditions and the amplitude of the derivative of the parameter has passed a predetermined threshold, responsively establishing a zero position of the motor.

Abstract: A voltage regulated transistor driver receives an electrical communication of a source voltage from a voltage source, and in response thereto, electrically communicates a regulated driver voltage to one or more transistors for the purpose of driving the transistor(s). In a voltage multiplier mode of the transistor driver, the regulated driver voltage is greater than the source voltage. In a voltage follower mode of the transistor driver, the regulated driver voltage approaches the source voltage to thereby equal or approximate the source voltage.

Abstract: The present invention includes a method for controlling brake motor. The method includes receiving brake motor information, determining a first brake motor voltage value and a brake motor current value based on the motor information when the brake motor is active, determining a brake motor resistance value based on the first brake motor voltage value and the brake motor current value, determining a brake motor temperature value based on the determined brake motor resistance value, and producing a brake motor control signal based on the determined brake motor temperature value. The method may additionally include determining a second brake motor voltage value when the brake motor is inactive, and producing a motor diagnostic voltage value based on the determined second brake motor voltage value.

Abstract: A method for detecting a change in permeability of a magnetostrictive object due to a change in strain. At least one first coil and at least one second coil are obtained and positioned such that magnetic flux lines induced by an electric current in the first coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, such that magnetic flux lines induced by an electric current in the second coil(s) pass through at least one portion of the object in a direction substantially parallel to the strain direction, and such that any electromagnetic interference sensed by the first coil(s) is sensed oppositely by the second coil(s). The total inductance of the positioned first and second coil(s) is measured over time. A change in permeability of the object is detected from a change in the measured total inductance over time.

Abstract: A method and circuit for detecting a change in inductance of a variable inductance element. An oscillating signal has a frequency that varies with inductance of the element. An intermediate voltage is produced at a level that varies according to frequency of the oscillating signal. The intermediate voltage is scaled to produce an output voltage.

Abstract: A mounting bracket apparatus for a disc brake of a vehicle is provided for measuring torque in a disc brake mounting bracket. The invention includes a bracket capable of being secured to a non-rotatable part of a vehicle. The bracket includes first and second caliper bracket abutments and a cross member extending in the direction of the rotational axis of the disc. The cross member joins the first and second caliper bracket abutments at respective first and second corner-shaped portions. A force sensor is located adjacent the first corner-shaped portion of the bracket adapted to sense strain in the first corner-shaped portion.

Abstract: A mounting bracket apparatus for a disc brake of a vehicle is provided for measuring torque in a disc brake mounting bracket. The invention includes a bracket capable of being secured to a non-rotatable part of a vehicle. The bracket includes first and second caliper bracket abutments and a cross member extending in the direction of the rotational axis of the disc. The cross member joins the first and second caliper bracket abutments at respective first and second corner-shaped portions. A force sensor is located adjacent the first corner-shaped portion of the bracket adapted to sense strain in the first corner-shaped portion.

Abstract: A brake system comprising a hydraulic brake, wherein the brake includes a displaceable braking surface, wherein the hydraulic brake requires low pressure to effect displacement during initiation of a brake apply and increased pressure to effect displacement as brake apply progresses, wherein the increased pressure exponentially increases in a non-linear response curve, a motor driven hydraulic actuator having a rotary input provided by a motor and a hydraulic output coupled to the hydraulically actuated brake, wherein the rotary input requires low torque during the initiation of brake apply to effect displacement of the hydraulically actuated brake and requires increased torque to effect rotary motion and displacement of the hydraulically actuated brake as brake apply progresses, the motor characterized by a progressively changing non-linear operation having a low torque mode and a high torque mode, and a control apparatus for the motor controlling the motor to effect displacement of the hydraulic brake, wher

Abstract: A multiple phase full wave motor drive transistor bridge inverter control circuit in which the base drive power supply for the transistors is transformer isolated from the on/off logic circuits, and the current control function for all of the inverter transistors is performed by a single current regulation circuit. A separate transformer is provided for each phase of the bridge inverter, and the transformer primaries are connected series to form the load of the current regulation circuit. The transformer secondaries supply base current to the upper and lower transistors of each respective phase, and the logic circuits schedule the conduction of the inverter transistors such that one transistor of each phase is always conductive, neglecting dead time. Each of the secondary circuits includes an impedance matching circuit to maintain balanced loading under conditions wherein the inverter transistors are reverse biased due to lagging power factor motor winding currents.

Abstract: An AC motor control based on an iterative computation of the motor load and method of accurately determining motor load. At the initiation of motor operation, the load term (%LOAD) is initialized to zero, and the motor is energized in accordance with a predetermined voltage and frequency schedule for producing motor rotation. During the starting interval the power loss term LOSSES and the load term (%LOAD) are iteratively computed as a function of the input voltage and current (V.sub.bus, I.sub.bus) and the motor inverter frequency (IF). When a predetermined motor speed has been achieved, the run mode is initiated. At this point, the load is known based on the iterative load calculations performed during starting, and the motor voltage and inverter frequency are scheduled as a function of motor speed and load. The iterative computation of losses and load continue during the run mode so that changes in the motor load are taken into account.

Abstract: An FET bridge protection circuit preventing shoot-through caused from both FETs being biased on at the same time, while also maximizing the frequency at which the bridge output can alternate between high and low is described.

Abstract: The disclosure describes an impedance matching circuit for maintaining the input impedance, of a drive transistor as sensed by a driver circuit, substantially constant. The circuit is connected to the input of the drive transistor such that when the drive transistor is forward biased, the input impedance sensed by the drive circuit is the input impedance of the drive transistor, and when the drive transistor is reverse biased, the input impedance sensed by the driver circuit is the combination of the input impedance of the drive transistor and an impedance of the matching circuit.

Abstract: A switching circuit for and inductive load with a parallel freewheeling diode comprises a semiconductor switch in series therewith across a power supply and a switch control effective to change the semiconductor switch from a nonconducting to a conducting state by sourcing current to the control electrode to charge the internal capacitance. The switch control means is responsive to the load voltage to produce a lower current rate to the control electrode while the load voltage indicates a condition other than reverse bias for the freewheeling diode in order to reduce RFI by slowing the switching of the semiconductor switch while the freewheeling diode is recovering and a higher current rate as soon as the load voltage indicates reverse bias for the freewheeling diode in order to minimize time spent in the active conduction region of the semiconductor switch and thus minimize resultant heat generation during switching.

Abstract: A power window control circuit for a motor vehicle includes a FET and SCR in series across the power supply with their junction connected to one side of a motor armature, the other side of the motor armature being switchable between power supply terminals. To provide reverse battery protection, no anti-parallel diode is provided around the SCR. The activation circuit for the FET includes a capacitor bootstrap circuit controlled by a switching transistor and a zener diode from the drain to the gate. When conduction from the switch through the motor and SCR is stopped, the inductive energy from the armature windings dissipates through the internal anti-parallel diode of the FET. When opposite conduction from the FET through the motor and switch is stopped, the inductive energy causes the voltage across the FET to rise to the zener voltage and turn on the FET sufficiently to dissipate it.

Abstract: A pulse width modulated DC motor operating system is disclosed which reduces the communication back to the power supply of transient spikes caused by the switching characteristics of the freewheeling diode. The switched current path comprises, in series, a DC power supply, a low pass filter including charge storage means, a DC motor armature, a FET and a resistor. A freewheeling diode is connected across the motor armature. PWM signal generating apparatus switches the FET to control average motor armature current. A capacitor is connected across the FET and diode with minimal lead length to reduce stray inductance.